Discussion
For \( R = 1 \ \mathrm{k\Omega} \), \( B = 1 \ \mathrm{MHz} \) at \( 290 \ \mathrm{K} \), the noise voltage is about
Answer: A
Substituting into the voltage expression:
\[ \begin{aligned} \overline{v^{2}} &= 4kTBR \\ &= 1.6 \times 10^{-11} \ \mathrm{V^{2}} \\ v &= 4.0 \ \mathrm{\mu V} \end{aligned} \]
so about 4 microvolts root mean square. The other options are decade errors either way. This is the figure that sets what a high-impedance input can usefully resolve, and it explains why sensitive front ends are built at low impedance.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development